Dr. Oz says education is key to curbing child obesity in the future. "Instead of trying to diet hard, we've got to diet smart. If you understand the biology of blubber, it becomes easier to do it."

Dr. Brandt says she thinks the obesity epidemic is a failure of society—but one that is fixable. To demonstrate her point, she uses cigarettes as an example. "The first reaction was, 'Cigarettes aren't that bad for you'—and it took about five years before people said, 'Well, yes, it is bad for you,'" she says. After another 10, 15 years, Dr. Brandt says there was a real movement to stop smoking. "I think that's where we are with this obesity epidemic," she says. "We have announced it. They're starting to get it. And 15 years from now, I hope I'm out of business."

In the end, Dr. Oz says the children are the key to change. "You're going to go back into our homes, into our communities, you're going to be the activists that will change this entire equation, and it will be you who drive this whole movement."